From 0825f220fe4bd321d7182656a94bfba4435aa72d Mon Sep 17 00:00:00 2001
From: orklah <ronan_morin@hotmail.com>
Date: Sat, 4 Sep 2021 20:22:06 +0200
Subject: [PATCH 1/2] allow ternary to override previous type when reassigning

---
 .../Statements/Expression/TernaryAnalyzer.php        | 12 ++++++++++++
 tests/TypeReconciliation/ConditionalTest.php         | 11 ++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/TernaryAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/TernaryAnalyzer.php
index ad3adad6c6d..ec95304e074 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/TernaryAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/TernaryAnalyzer.php
@@ -15,6 +15,7 @@
 use Psalm\Type\Reconciler;
 
 use function array_filter;
+use function array_intersect;
 use function array_keys;
 use function array_map;
 use function array_merge;
@@ -232,6 +233,17 @@ function ($c) use ($reconciled_expression_clauses): bool {
             }
         }
 
+        $redef_var_ifs = array_keys($if_context->getRedefinedVars($context->vars_in_scope));
+        $redef_var_else = array_keys($t_else_context->getRedefinedVars($context->vars_in_scope));
+        $redef_all = array_intersect($redef_var_ifs, $redef_var_else);
+
+        foreach ($redef_all as $redef_var_id) {
+            $context->vars_in_scope[$redef_var_id] = Type::combineUnionTypes(
+                $if_context->vars_in_scope[$redef_var_id],
+                $t_else_context->vars_in_scope[$redef_var_id]
+            );
+        }
+
         $context->vars_possibly_in_scope = array_merge(
             $context->vars_possibly_in_scope,
             $if_context->vars_possibly_in_scope,
diff --git a/tests/TypeReconciliation/ConditionalTest.php b/tests/TypeReconciliation/ConditionalTest.php
index 5872f54252c..3de456b017e 100644
--- a/tests/TypeReconciliation/ConditionalTest.php
+++ b/tests/TypeReconciliation/ConditionalTest.php
@@ -2665,7 +2665,16 @@ function ($_valid): void {};
                          $takesValid($val3);
                      }
                  }'
-            ]
+            ],
+            'ternaryRedefineAllVars' => [
+                '<?php
+                    $_a = null;
+                    $b = rand(0,1) ? "" : "a";
+                    $b === "a" ? $_a = "Y" : $_a = "N";',
+                'assertions' => [
+                    '$_a===' => "'N'|'Y'",
+                ]
+            ],
         ];
     }
 

From e2b594820e98f15922bf832edb33229873efaf54 Mon Sep 17 00:00:00 2001
From: orklah <ronan_morin@hotmail.com>
Date: Sat, 4 Sep 2021 20:27:25 +0200
Subject: [PATCH 2/2] fix test

---
 tests/TypeReconciliation/ConditionalTest.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/TypeReconciliation/ConditionalTest.php b/tests/TypeReconciliation/ConditionalTest.php
index 3de456b017e..5975d5f1493 100644
--- a/tests/TypeReconciliation/ConditionalTest.php
+++ b/tests/TypeReconciliation/ConditionalTest.php
@@ -2672,7 +2672,7 @@ function ($_valid): void {};
                     $b = rand(0,1) ? "" : "a";
                     $b === "a" ? $_a = "Y" : $_a = "N";',
                 'assertions' => [
-                    '$_a===' => "'N'|'Y'",
+                    '$_a===' => '"N"|"Y"',
                 ]
             ],
         ];